Whole-building ventilation system

ABSTRACT

A whole-building ventilation system includes a duct unit and a fan unit. The duct unit includes an inlet housing and a duct having a first end coupled to the inlet housing and a second end spaced apart from the first end. The fan unit is coupled to the duct to displace air through the duct. The whole-building ventilation system further includes a mount system configured to suspend the second end of the duct and the fan unit from a structure.

PRIORITY CLAIM

This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 63/111,692, filed Nov. 10, 2020, which is expressly incorporated by reference herein.

BACKGROUND

The present disclosure relates to a ventilation system, and particularly to a ventilation system arranged in an attic space of a building. More particularly, the present disclosure relates to a ventilation system for ventilating the entire building.

SUMMARY

According to the present disclosure, a whole-building ventilation system is provided in a building having an attic space and a living space separated from the attic space by a ceiling or walls. The whole-building ventilation system is located in the attic space and is configured to draw air from the living space and discharge the air into the attic space while at least one living space aperture is opened so that fresh outside air is drawn into the living space and hot exhaust air is forced out of at least one vent in the attic space so that the entire interior of the building may be ventilated with fresh outside air.

In illustrative embodiments, the whole-building ventilation system includes a duct unit, a fan unit coupled to the duct unit, and a mount system that couples the fan unit to an overhead structure in the attic space. The duct unit extends between the living space and the fan unit to direct air there between when the fan unit is in operation. The fan unit is coupled to an end of the duct unit within the attic space. The mount system suspends the fan unit above the ceiling of the living space so that the fan unit is positioned in a generally central region of the attic space to maximize ventilation of the attic space and airflow through the whole-building ventilation system.

In illustrative embodiments, the mount unit includes a plurality of brackets coupled to the fan unit, a plurality of lanyards coupled to the overhead structure, and an energy-absorption system. At least one lanyard of the plurality of lanyards is coupled to a corresponding one bracket of the plurality of brackets by the energy absorption system. The energy-absorption system increases the resiliency of the mount system so that transfer of vibrations from the fan unit to the overhead structure is reduced or eliminated.

In illustrative embodiments, the whole-building ventilation system may further include an inlet air-distributor and an outlet air-diffuser that help optimize the airflow through the duct unit and the fan unit. The inlet air-distributor is configured to guide air flowing through the fan unit in a straight line. The outlet air-diffuser controls discharge of air from the fan unit to optimize the airflow.

In illustrative embodiments, the fan unit is controlled by a control system to regulate a flowrate of air through the whole-building ventilation system while minimizing vibrations caused as a result of natural resonate frequencies of components in the whole-house ventilation system. The fan unit includes an electronically commutated (EC) motor having a linearly variable rotation speed so that a flow rate of air can be changed on a linear basis. The motor may be controlled wirelessly by a remote device.

Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The detailed description particularly refers to the accompanying figures in which:

FIG. 1 is a side elevation view of a building with a side wall of the building removed to show that the building is formed to include a living space and an attic space and showing a whole-building ventilation system located in the attic space to draw air from the living space into the attic space and to push air out of attic vents while a window or door to the living space is opened so that fresh outside air is pulled into the living space to ventilate the entire building;

FIG. 2 is a perspective and diagrammatic view of the whole-building ventilation system from FIG. 1 showing that the whole-building ventilation system includes a duct unit having an inlet port opening into the living space, a fan unit coupled to the duct unit and located in the attic space; and a mount system configured to suspend the fan unit from an overhead structure in the attic space while minimizing transmission of vibrations from the fan unit to the overhead structure;

FIG. 3 is an exploded assembly view of the whole-building ventilation system showing, from left to right, the duct unit including an inlet housing and an insulative duct, the fan unit including an inlet-air distributor, a fan housing, a plurality of fan blades, a motor and a plurality of support struts, and the mount system separated from the fan unit and including a pair of side brackets, a plurality of lanyards, and a plurality of rubber grommets coupled between each of the lanyards and the plurality of brackets;

FIG. 4 is an enlarged view of the fan unit showing that the pair of brackets are mounted on opposite sides of the fan housing and the plurality of blades and the motor are located within a flow path defined by the fan housing and supported in the flow path by the plurality of support struts along a central axis;

FIG. 5 is an elevation view of the fan unit looking directly at an outlet of the fan unit to show each of the brackets having a curved shape and coupled to two struts of the plurality of struts to establish a direct load-transferring path from the motor to the plurality of rubber grommets so that the rubber grommets minimize transmission of vibrations from the motor to the overhead structure;

FIG. 6, is an enlarged view of a portion of FIG. 5 showing one of the brackets of the plurality of brackets mounted on the fan housing and showing a companion lanyard coupled to the bracket using a fastener;

FIG. 7 is a partial exploded view of the whole-building ventilation system showing the inlet-air distributor coupled to an end of the duct unit to straighten the air prior to the air reaching the plurality of blades;

FIG. 8 is a partial perspective view showing an optional diffuser included in the fan unit coupled to a downstream end of the fan housing to increase efficiencies of the airflow being discharged by the fan unit into the attic space; and

FIG. 9 is a perspective and diagrammatic view of the whole-building ventilation system showing that the whole-building ventilation system further includes a control system that is configured to receive user inputs into a remote device to wirelessly control operation of the whole-building ventilation system.

DETAILED DESCRIPTION

A building 10 is shown diagrammatically in FIG. 1 as a house having a living or occupancy space 12 and an attic or utility space 14 separated from the living space 12. The building 10 is formed to include one or more windows and doors (collectively referred to as living space apertures 16) that open into the living space 12 and one or more vents 18 that open into the attic space 14. A whole-building ventilation system 20, in accordance with the present disclosure, is located in the attic space 14 and is configured to draw air from the living space 12 and discharge the air into the attic space 14 while at least one living space aperture 16 is opened so that fresh outside air 22 is drawn into the living space 12. Hot exhaust air 24 is forced out of the at least one vent 18 in the attic space 14 as the air from the living space 12 is drawn through the whole-building ventilation system 20 and discharged into the attic space 14. After a period of time, the entire interior of the building 10 may be ventilated with fresh outside air 22 using the whole-building ventilation system 20.

The whole-building ventilation system 20 (also referred to as whole-house ventilation system 20) is positioned such that an inlet port 26 opens into the living space 12 as shown in FIG. 1. At least a portion of the whole-building ventilation system 20 is suspended from an overhead structure 28 in the attic space 14 to position an outlet port 30 within the attic space 14 to maximize ventilation of the building 10. The overhead structure 28 may be a designated structure coupled to building 10 and specifically designed to support the whole-building ventilation system 20 or a structural component of the building 10 such as a ceiling joist, roof rafter, beam, or any other suitable structure in the attic space 14.

The whole-building ventilation system 20 includes a duct unit 32, a fan unit 34 coupled to the duct unit 32 and configured to displace air to ventilate the building 10, and a mount system 36 that couples the fan unit 34 to the overhead structure 28 as shown in FIG. 2. The duct unit 32 extends between the living space and the fan unit 34 to carry air there between when the fan unit 34 is in operation. The fan unit 34 is coupled to an end 38 of the duct unit 32 within the attic space 14. The mount system 36 suspends the fan unit 34 and the end 38 of the duct unit 32 above ground so that the fan unit 34 is positioned in a generally central region of the attic space 14, as shown in FIG. 1, to maximize ventilation of the attic space 14 and airflow through the whole-building ventilation system 20.

The duct unit 32 includes an inlet grate 40, an inlet housing 42, and an insulative duct 44 as shown in FIG. 2. The inlet grate 40 is covers the inlet port 26 and is aligned with an aperture in a ceiling or wall of the living space 12 that leads to the attic space 14. The inlet grate 40 may be a fixed grate that is always open, or the inlet grate 40 may include a plurality of movable damper plates that open and close the inlet port to provide a damper for the inlet grate 40. Each of the movable plates may be insulated to block transfer of heat and noise. The inlet housing 42 is a rectangular prism that is sized to fit over the aperture between the living space 12 and the attic space 14. A first end 37 of the insulative duct is coupled to the inlet housing 42 and has an elliptical cross section. A second end 38 of the insulative duct 44 is coupled to the fan unit 34 and has a circular cross section.

The insulative duct 44 is flexible to assume a curved shape when viewed from the side to optimize the flow of as shown in FIGS. 2 and 3. The curved shape is continuous and parabolic such that its slope at end 37 is greater than its slope at end 38. The insulative duct 44 makes a 90 degree turn from the first end 37 to the second end 38 and is held in the curved shape by the mount system 36. The insulative duct includes an outer foil layer 46, a fiberglass layer 48, and an inner cloth layer 50. The outer foil layer 46 is fluid impermeable so that no air escapes through the insulative duct 44. The fiberglass layer 48 insulates the duct 44 to block transfer of heat and noise. The inner cloth layer 50 is spaced apart from the outer foil layer 46 by the fiberglass layer 48 and defines a duct flow path 52 of the insulative duct 44. The mount system 36 is coupled only to the fan unit 34 to minimize pinch points in the insulative duct 44 so that the continuous curved shape is maintained to optimize airflow through the duct flow path 52.

The fan unit 34 is coupled to the second end 38 of the insulative duct 44 and includes a fan housing 54, a motor 56, a plurality of fan blades 58, and a plurality of support struts 60 as shown in FIGS. 2 and 3. The fan housing 54 defines a fan flow path 62 that is in fluid communication with the duct flow path 52 and extends along a central axis 64. The motor 56 is arranged to lie in the flow path 62 and is configured to drive rotation of the fan blades 58. The plurality of fan blades 58 are coupled to the motor 56 for rotation about the central axis 64 to displace air through the flow paths 52, 62 of the whole-building ventilation system 20 from the living space 12 to the attic space 14. The plurality of support struts 60 interconnect the fan housing 54 and the motor 56 to support the motor 56 and the plurality of fan blades 58 in the flow path 62 of the fan unit 34. Each of the plurality of support struts 60 are angled in the same direction relative to the central axis 64 to optimize airflow downstream away from the fan blades 58.

The motor 56 and/or the plurality of fan blades 58 may cause undesirable vibrations and noise as a result of the vibrations during operation of the fan unit 34. The mount system 36 is configured to reduce transmission of the vibrations caused by the motor 56 and/or the plurality of fan blades 58 from the fan unit 34 to the structure 28 that couples the fan unit 34 to the building 10. The mount system 36 includes a plurality of brackets 66 coupled to the fan housing 54, a plurality of lanyards 68 coupled to the overhead structure 28, and an energy-absorption system 70 coupled between each bracket 66 and each corresponding lanyard 68 as shown in FIGS. 3 and 4. The plurality of brackets 66 extend outwardly from an outer surface 55 of the fan housing 54 to provide separation from the fan housing 54. At least one lanyard 68 of the plurality of lanyards 68 is coupled to a corresponding one bracket 66 of the plurality of brackets 66 by the energy-absorption system 70. In some embodiments, the plurality of brackets 66 may be omitted such that the energy-absorption system 70 is coupled directly to the fan unit 34. The energy-absorption system 70 increases the resiliency of the mount system 36 so that transfer of vibrations is reduced or eliminated.

The energy-absorption system 70 includes a companion set of one fastener 72 and one rubber grommet 74 for each lanyard 68 as shown in FIGS. 3-6. Each fastener 72 is illustratively embodied as an eye bolt, but other types of fasteners may be used. Each rubber grommet 74 is a cylindrical component that is sized to fit within an aperture 76 formed in each bracket 66 and/or another part of the fan unit 34. Each grommet 74 is also formed to include a fastener-receiving passageway 78. Each fastener 72 is arranged to extend through a companion fastener-receiving passageway 78 to couple with a companion rubber grommet 74. The fastener 72 may be threaded with the rubber grommet 74 or may include a retainer such as a nut that blocks removal of the fastener 72 from the fastener-receiving passageway 78. The rubber grommet 74 provides spacing between its companion bracket 66 and fastener 72 such that the fasteners 72 do not directly engage the brackets 66 and/or the fan unit 34. In this way, the rubber grommets 74 buffer transmission of vibrations from the fan unit 34 to the lanyards 68 and the overhead structure 28 of the building 10. In some embodiments, the fasteners 72 may be omitted and the lanyards 68 can be directly coupled to the rubber grommets 74.

Each of the brackets 66 cooperates with one or more of the support struts 60 to provide a direct load path between the motor 56 and the energy-absorption system 70 as shown in FIGS. 5 and 6. Each bracket 66 is coupled to the fan unit 34 by a companion bracket fastener 80 that extends through the fan housing 54 and couples with one of the plurality of support struts 60 to establish the direct load path. A portion of each bracket 66 is curved to match the fan housing 54 and has a length that extends between at least two struts 60 of the plurality of struts 60. Each of the two struts 60 receives a corresponding bracket fastener 80 such that each bracket 66 is directly coupled to at least two struts 60 of the plurality of struts thereby increasing support and energy absorption of the mount system 36 as a whole. In some embodiments, each bracket 66 may extend between more than two struts 60. In some embodiments, only one bracket 66 may be used and may be coupled to each strut of the plurality of struts 60 by bracket fasteners 80.

Each bracket 66 includes a housing mount 82 coupled to the fan housing 54 and a lanyard mount 84 coupled to the housing mount 82 and spaced apart from the fan housing 54 as shown in FIGS. 3-6. Each housing mount 82 includes a housing-mount body 86 that is curved to extend partway around the central axis 64 between two struts of the plurality of struts 60 and a pair of housing-mount flanges 88 that are each aligned with one strut of the plurality of struts 60. Each housing-mount flange 88 is configured to receive one bracket fastener 80 to couple each bracket 66 to the two struts of the plurality of struts 60. Each lanyard mount 84 is coupled to a corresponding set of one fastener 72 and one rubber grommet 74 of the energy-absorption system 70 to couple one of the lanyards of the plurality of lanyards 68 to each bracket 66.

The plurality of lanyards 68 cooperate with one another to provide a multi-directional suspension system that blocks movement of the fan unit 34 in all directions generally normal to a direction of gravity 90 (i.e. a swinging motion) as shown in FIGS. 2 and 5. Each lanyard of the plurality of lanyards is adjustable and flexible so that each lanyard can be mounted on an overhead structure 28 an oriented relative to one another to establish the multi-direction suspension system. Each lanyard 68 may be arranged to extent outward away from one another as the lanyards 68 extend from the fan unit 34 to the overhead structure so that movement of the fan unit 34 in all directions normal to the direction of gravity 90 are blocked. In the illustrative embodiment, three lanyards 68 are included in the plurality of lanyards to provide a tri-pod suspension, however, in other embodiments, any number of lanyards 68 may be used to suspend the fan unit 34 from the overhead structure 28 while providing the multi-directional suspension system. To provide the tri-pod suspension, at least one of the lanyards 68 is offset from the other lanyards 68 that are coupled to corresponding brackets 66 along a length of the fan unit 34 relative to the central axis 64. The at least one lanyard 68 that is offset from the other lanyards 68 may be coupled directly to the fan unit 34 without a bracket 66 and in a central location relative to the two other lanyards 68 as shown in FIG. 3.

Each lanyard 68 of the plurality of lanyards 68 includes a tether 92, a coupler 94, and a length adjuster 96 as shown in FIG. 3. The tether 92 may be a rope, wire, wire braid, strap, or another suitable elongated structure that can provide tensile support to suspend the fan unit 34 from the overhead structure 28. The coupler 94 is attached at one end of the tether 92 and is configured to couple with a companion fastener 72. The coupler 94 may be a clasp, hook, or another suitable structure to attach the lanyard 68 to the fastener 72 or the rubber grommet 74. The length adjuster 96 is coupled to the tether 92 and is configured to receive an end of the tether 92 opposite the coupler 94 to form a loop 97. The loop 97 is adjustable by moving the tether 92 relative to the length adjuster 96 to change a length of the tether 92 and/or resize the loop 97 to wrap around the overhead structure 28. The length adjuster 96 includes one or more clamps or cleats to block movement of the tether 92 relative to the length adjuster 96 once a desired length of the tether and/or size of the loop 97 is achieved.

The plurality of lanyards 68 provide a method of facilitating installation of the whole-building ventilation system 20 to ensure that airflow through duct unit 32 is optimized. To install the whole-building ventilation system 20, the tether 92 of each lanyard 68 is first wrapped around the overhead structure(s) 28 and attached to the length adjuster 96 to form the loop 97 that couples each lanyard to the overhead structure(s) 28. The tether 92 may be oversized so that any overhead structure 28 can be reached. The length of each tether 92 may then be adjusted slightly to an estimated length that is sufficient to suspend the fan unit 34 at an appropriate height relative to the inlet housing 42. The fan unit 34 may then be attached to each lanyard 68 using the couplers 94. Once all of the lanyards 68 are attached to the fan unit 34, the length of each tether 92 may be further adjusted using each length adjuster 96 until the fan unit 34 is at an appropriate height relative to the inlet housing 42 to establish the curvature of insulative duct 44 that optimizes airflow through the duct unit 32 as shown in FIG. 1. In this way, each lanyard 68 provides a pulley system that facilitates lifting of the fan unit 34 to the desired height relative to the inlet housing 42 without the need for a technician to hold the fan unit 34 while simultaneously attempting to attach one or more straps to the overhead structure 28 with an adequate length. The length of each tether 92 may be readjusted as needed until the height of the fan unit 34 and/or a location of the components of the whole-building ventilation system 20 are in their desired locations for optimized airflow.

The whole-building ventilation system 20 may further include additional components that help optimize the airflow through the duct unit 32 and the fan unit 34 as shown in FIGS. 7 and 8. The whole-building ventilation system 20 may further include an inlet air-distributor 100 coupled to an upstream end 102 of the fan unit 34 and an outlet air-diffuser 104 coupled to a downstream end 106 of the fan housing 54. The inlet air-distributor 100 includes a plurality of air-straightening vanes 108 arranged in the flow path 62 and spaced circumferentially apart from one another about central axis 64. Each of the air-straightening vanes 108 extend through flow path 62 parallel with the central axis 64 to guide air flowing through the flow path 62 in a straight line to the plurality of fan blades 58. In the illustrative embodiment, the plurality of air-straightening vanes 108 includes four vanes that divide the flow path 62 into equally sized quadrants, however, any number of air-straightening vanes may be used. The outlet air-diffuser 104 has a frustoconical shape with a first diameter 110 at an upstream end 112 of the outlet air-diffuser 104 and a second diameter 114 at a downstream end 116 of the outlet air-diffuser 104 that is greater than the first diameter. The outlet air-diffuser 104 controls discharge of air from the fan unit 34 to optimize the airflow. The fan unit 34 may further include an optional outlet grate 118 coupled to the downstream end 106 of the fan housing 54 to block people or objects from extending toward fan blades 58.

The motor 56 of the fan unit 34 may be controlled by a control system 120 to regulate a rotation speed of the fan blades 58 and a flowrate of air through the flow paths 52, 62 as shown in FIG. 9. The control system 120 includes a microprocessor 122, a memory storage device 124, and communication circuitry 126. The microprocessor 122 is configured to send command signals to the motor to operate the motor 56 in response to receipt of one or more user inputs 128. The memory storage device 124 stores instructions that dictate operation of the motor 56 when executed by the microprocessor 122. The communication circuitry 126 allows the control system 120 to communicate with a user interface 130 and/or a remote device 132 to receive the user inputs 128.

The motor 56 is illustratively an electronically commutated (EC) motor having a rotor with a linearly variable rotation speed so that a flow rate of air can be changed on a linear basis. The EC motor 56 includes a brushless direct current (DC) motor with onboard electronics. In this way, the EC motor 56 may run on alternating current (AC) power while using a brushless DC motor to increase power and rotation speed efficiencies in comparison to standard DC motors without integrated electronics and AC motors.

The fan blades 58 can be rotated by the EC motor 56 at any rate between a maximum and zero. The fan blades 58 and the structures surrounding the fan blades 58 may vibrate at certain rotational speeds of the fan blades due to their natural resonate frequency. As such, the EC motor 56 allows a user to adjust the rotational speed of the fan blades 58 in small increments to avoid a rotational speed that causes vibrations while still allowing a user to set a flow rate that is at or close to a desired flow rate. Other types of motors such as alternating current motors are not linearly variable and may include a set number of rotational speeds that change the flow rate in steps and don't allow the user to pick a speed between those steps. If vibrations occur at one of the set speeds, a user may be forced to tolerate the vibrations or change the flow rate to a different, undesired flow rate where the vibrations do not occur.

The user interface 130 may be mounted to a wall in the living space 12 and connected to the communication circuitry 126 by a wired connection. The user inputs 128 may be directly input into the user interface 130 and relayed to the control system 120 to control the motor 56. Alternatively, the communication circuitry 126 and the user interface 130 may each include components to allow for wireless communication between the control system 120 and the user interface 130. Both the control system 120 and the user interface 130 may include one or more antennas or transceivers to allow the control system 120 and the user interface 130 to send and receive signals and data wirelessly. The user interface 130 may also include its own microprocessor and memory storage device storing instructions that, when executed by the microprocessor, controls operation of the user interface 130 to send signals to the control system 120.

In some embodiments, the user may input the user inputs 128 into the remote device 132 as shown in FIG. 9. The remote device 132 is configured to communicate wirelessly with the user interface 130 or directly with the communication circuitry 126 of the control system 120. The remote device 132 may be a smartphone, tablet, laptop, remote control, a virtual assistant device or any other suitable remote device. 

1. A whole-building ventilation system for drawing air from a living space of a building into an attic space of the building to cause fresh outside air to be pulled through an aperture opening into the living space, the ventilation system comprising a duct unit including an inlet housing with an inlet port that opens into the living space of the building and an insulative duct having a first end coupled to the inlet housing and a second end spaced apart from the first end to provide an outlet port opening toward the attic space of the building, a fan unit including a fan housing that defines a flow path and extends circumferentially around a central axis, a motor arranged to lie within the flow path along the central axis, a plurality of support struts that interconnect the fan housing and the motor to support the motor within the flow path, and a plurality of blades coupled to the motor for rotation about the central axis to displace air from the living space, through the duct unit, and into the attic space, and a mount system configured to suspend the second end of the insulative duct and the fan unit from an overhead structure in the attic space, the mount system including a plurality of brackets coupled to an outer surface of the fan housing, a plurality of adjustable lanyards, at least one lanyard of the plurality of lanyards being coupled to each bracket of the plurality of brackets, and a plurality of rubber grommets, wherein one rubber grommet of the plurality of rubber grommets is fixed to each bracket of the plurality of brackets and located between each bracket and each lanyard to reduce transmission of vibrations caused by the motor from the fan unit to the overhead structure from which the fan unit is suspended.
 2. The ventilation system of claim 1, wherein each bracket is coupled to the fan unit by at least one bracket fastener that extends through the fan housing and is coupled to at least one support strut of the plurality of support struts.
 3. The ventilation system of claim 2, wherein each bracket includes a curved housing mount coupled to the fan housing and a lanyard mount coupled to the housing mount and spaced apart from the fan housing.
 4. The ventilation system of claim 3, wherein the curved housing mount of each bracket is sized to extend partway around the central axis to interconnect two struts of the plurality of struts.
 5. The ventilation system of claim 1, wherein at least one lanyard of the plurality of lanyards and a corresponding rubber grommet of the plurality of rubber grommets is spaced apart from the plurality of brackets so that the plurality of lanyards provide a multi-directional suspension system that blocks movement of the duct unit and the fan unit in all directions normal to a direction of gravity.
 6. The ventilation system of claim 1, wherein the plurality of brackets includes a first bracket coupled to a first lateral side of the fan housing and a second bracket coupled to an opposite second side of the fan housing and the plurality of lanyards includes a first lanyard coupled to the first bracket, a second lanyard coupled to the second bracket, and a third lanyard coupled to the fan unit and spaced apart from the first bracket and the second bracket relative to the central axis so that the first lanyard, the second lanyard, and the third lanyard cooperate to provide a tri-pod suspension.
 7. The ventilation system of claim 1, wherein the fan unit further includes an outlet diffuser coupled to a downstream end of the fan housing, the outlet diffuser having a conical shape with a first diameter at the downstream end of the fan housing and a second diameter greater than the first diameter at a downstream end of the outlet diffuser.
 8. The ventilation system of claim 7, further comprising an inlet air-distributor coupled to an upstream end of the fan unit, the inlet air-distributor including a distributor housing and a plurality of guide vanes that straighten the air flowing from the insulative duct prior to reaching the plurality of blades.
 9. The ventilation system of claim 1, wherein each of the plurality of support struts is angled relative to the central axis.
 10. The ventilation system of claim 1, wherein the motor includes a direct-current motor having a linearly variable rotation speed so that a flow rate of air can be changed on a linear basis.
 11. The ventilation system of claim 10, further comprising a control system including a controller and communication circuitry configured to wirelessly communicate with a remote device to change the flow rate of air.
 12. A whole-building ventilation system comprising a duct unit including an inlet housing and an insulative duct having a first end coupled to the inlet housing and a second end spaced apart from the first end, a fan unit including a fan housing that defines a flow path and extends along a central axis, a motor, a plurality of support struts arranged within the flow path, and a plurality of blades driven by the motor to displace air through the duct unit, and a mount system configured to suspend the second end of the insulative duct and the fan unit from a structure, the mount system including an energy-absorption system configured to reduce transmission of vibrations from the fan unit to the structure from which the fan unit is suspended.
 13. The whole-building ventilation system of claim 12, wherein the mount system further includes a plurality of brackets coupled to an outer surface of the fan housing and a plurality of adjustable lanyards, at least one lanyard of the plurality of lanyards being coupled to each bracket of the plurality of brackets, and the energy-absorption system includes a plurality of rubber grommets.
 14. The whole-building ventilation system of claim 13, wherein at least one lanyard of the plurality of lanyards is coupled to each bracket of the plurality of brackets and one rubber grommet of the plurality of rubber grommets is located between each bracket and each lanyard.
 15. The whole-building ventilation system of claim 14, wherein each bracket is coupled to the fan unit by at least one bracket fastener that extends through the fan housing and is coupled to at least one support strut of the plurality of support struts.
 16. The ventilation system of claim 13, wherein each bracket includes a curved housing mount coupled to the fan housing and a lanyard mount coupled to the housing mount and spaced apart from the fan housing.
 17. The ventilation system of claim 16, wherein the curved housing mount of each bracket is sized to extend partway around the central axis to interconnect two struts of the plurality of struts.
 18. The ventilation system of claim 13, wherein the plurality of brackets includes a first bracket coupled to a first lateral side of the fan housing and a second bracket coupled to an opposite second side of the fan housing and the plurality of lanyards includes a first lanyard coupled to the first bracket, a second lanyard coupled to the second bracket, and a third lanyard coupled to the fan unit and spaced apart from the first bracket and the second bracket relative to the central axis so that the first lanyard, the second lanyard, and the third lanyard cooperate to provide a tri-pod suspension.
 19. A method of installing a whole-building ventilation system in a building, the method comprising the steps of attaching a plurality of lanyards to an overhead structure, adjusting a length of each lanyard to an estimated length that corresponds to a desired height at which a fan unit of the whole-building ventilation system is to be suspended above a surface, attaching each lanyard to the fan unit after the step of adjusting, re-adjusting the length of each lanyard after attaching each lanyard to the fan unit to raise or lower the fan unit until a duct extending from the surface to the fan unit extends along a curve that maximizes air flow through the duct.
 20. The method of claim 19, wherein the duct makes a 90 degree turn from the surface to the fan unit and the curve is parabolic. 